1. Field of the Invention
The present invention relates to a display label and a method of forming a display label.
2. Description of the Related Art
Conventionally, various design patterns such as picture patterns, letters, symbols, photographs, or the like have been displayed as visually identifiable information on a member which is referred to hereinafter as a "member on which the information is to be displayed". This visually identifiable information (display information) may be, for example, a logo or the like which is directly applied to a tire or the like. In a case in which a logo or the like is displayed on a tire, the logo is stamped on the tire. More specifically, a patterned mold, which forms the pattern of the information to be displayed (display information), is formed within a mold which is used for the vulcanization of a tire. The green tire, which has already been subjected to a forming process, is placed into the patterned mold when the green tire is to be vulcanized. Simultaneously with the vulcanization of the tire, the surface of the tire is pressed onto the inside surface of the patterned mold due to the pressure from the internal portion of the tire so that letters or the like can easily be stamped on the surface of the tire.
Further, the aforementioned design patterns can be displayed by using a display label. For example, when a design pattern is displayed on a tire, a display label is applied to the surface of a tire during a vulcanization process of the tire. To this end, a display label is formed by using a heat resistant synthetic resin film as a base material. The display label is attached at a predetermined position of the tire while the tire is subjected to a vulcanization process (see Japanese Patent Application Laid-Open (JP-A) No. 59-55483).
A bar code label for a tire is a way in which information about the tire can be read and by which respective manufactured products can be managed during the production process or the distribution process thereof. The bar code label for a tire is attached to an unvulcanized green tire which has been subjected to a forming process, when the green tire is vulcanized, and is fixed to a tire during the vulcanization process. The bar code label for a tire can be attached to portions of a tire so as to extend from each bead portion to each side portion (but not at the tread portion). However, in a case in which the bar code labels are attached to the bead portions of a tire, rubber may flow during the vulcanization of the tire, thereby causing displacement of a position of the tire at which the label is attached. Accordingly, it is desirable that labels are attached at the side portions of the tire.
An example of the above-described type of bar code label is the symbol display label disclosed in Japanese Patent Application Laid-Open (JP-A) No. 59-55483. In this symbol display label, a rubber-based base material layer made of a crosslinked or semi-crosslinked rubber material is laminated on a rubber-based adhesive layer. Because the rubber-based base material layer is crosslinked before the vulcanization of the tire, the symbol display label is prevented from being deformed due to rubber flow during the vulcanization process of the tire, reading of the lot number of the tire is facilitated.
Japanese Utility Model Application Laid-Open (JP-U) No. 5-90539 discloses a display label which is structured by forming a heat transfer ink layer on the surface of a surface roughened, hardened resin membrane which has been formed on the surface of a heat resistant synthetic resin film. Accordingly, the heat transfer ink penetrates through the surface roughened, hardened resin membrane on the surface of the display label and strongly adheres so that printing can be carried out by using a heat transfer printer at the place of production. Moreover, since the display label has a rough surface which is made from a hardened resin membrane, the heat transfer ink is prevented from directly contacting the metal surface of a vulcanization mold and adhering thereto. As a result, a clear (legible) label can be formed.
Japanese Patent Application Laid-Open (JP-A) No. 7-306642 discloses a bar code label comprising a plastic film which includes a white filler and whose melting point is a temperature of 200.degree. C. or more. A surface of the film is subjected to a mat mold process and a rubber-based adhesive layer is provided on the other surface via a primer layer. Since the bar code label includes the plastic film, there is no heat deformation, such as shifting of positions, wrinkles, or the like, during the vulcanization process of the tire. Accordingly, at the place of production, the bar code label can be applied onto the surface of the plastic film at which the mat mold process has been effected, by being printed by using a heat transfer printer and an ink ribbon. Moreover, since a rubber-based adhesive layer is provided on the other surface of the plastic film via a primer layer, the bar code label is strongly adhered to a green tire during temporary attachment of the label to the tire and during the vulcanization process of a tire. Accordingly, phenomena such as shifting of positions or the like are not caused at the formed tire.
However, as described above, in a case in which a design pattern for displaying visible information is stamped on the surface of a tire, there arises a drawback in that a patterned mold must be manufactured for each design pattern. For this reason, the greater the number of types of display information, the larger the number of patterned molds. Accordingly, the manufacturing cost of a mold itself becomes expensive. Further, even when a portion of display information needs to be modified, a new mold must be manufactured. As a result, the expensive manufacturing cost of the mold leads to an expensive manufacturing cost of the tire.
The display label uses as a base material a heat resistant synthetic resin film which can expand and contract only slightly. Accordingly, there is a problem in that when a portion of a tire or the like on which display information is to be displayed is distorted, the display label deforms, a gap is formed between the display label and the surface of the portion of a tire or the like on which the display information is to be displayed, and the display label is liable to peel away from the aforementioned portion of the tire. Namely, even when a display label is attached to an expandable/contractible member on which display information is to be displayed, the display label cannot expand and/or contract in accordance with the expandability/contractibility of the member on which display information is to be displayed, and thus, the display label may peel off of the surface of the member on which display information is to be displayed. As a result, it becomes difficult to directly identify display information on the member on which display information is to be displayed.